ID_within V1 has been more than a theme build. It has been a full audit of how a Shopify theme behaves when it has to support real content.
Some issues only appear once the store has enough products, collections, blog articles, variants, and edge cases. Search needs article and page results. Blog tags need enough tags to test filtering. Product recommendations need related products. Collection cards need images, missing images, long titles, sale prices, and sold-out products.
That is why the next stage is content. The code can pass Theme Check and still need visual QA.
The biggest lesson is that a good theme needs both systems and proof. The systems make it reusable. The proof comes from testing those systems with real storefront content.
V1 is about getting the foundation clean. V2 can add more advanced features once the core theme is stable.